Tea anyone?

I'm still a coffee girl. I think the test of how English I become will be if I ever choose tea over coffee. I do enjoy tea with milk every once in a while but always prefer coffee.

Tea is something Americans see as "classically British" (along with biscuits and crumpets). But when people ask you if you'd like to come over for tea, they might actually mean dinner. To some people "tea" means the evening meal.

So what is the difference between tea and tea?
Am I supposed to eat before I come or are we eating?
Is there going to be real food or just biscuits?

I always have to clarify exactly what "tea" means when someone asks. So far I haven't been able to discern the answer from context clues alone...Just another example of confusing British words.